Apparatus for aseptic canning of food products



Oct. 1, 1963 F. D. HICKEY APPARATUS FOR ASEPTIC- CANNING OF FOODPRODUCTS Original Filed Oct. 7. 1957 mw om 3v 3 E.

m? wq A hm QN mm mm. PN mm mN INVENI'OR FRANK D. MICKEY By W I ATTORNEYUnited States Patent 3,105,335 AFPARATUS FOR ASFETIC CG OF FOOD PRODUCTSFrank D. Hickey, San Jose, Calif., assignor to FMC Corporation, acorporation of Delaware Application Nov. 21, 1958, Ser. No. 775,534,which is a division of application Ser. No. 688,590, Oct. 7, 1957 nowPatent No. 3,035,886, dated May 22, 1962. D1- vided and this applicationDec. 30, 1960, Ser. No.

3 Claims. (Cl. 53-127 The present invention pertains to an apparatus foraseptically packing food products in containers.

This application is a division of my copending application U.S. SerialNo. 775,534, filed November 21, 1958, now abandoned, for Method of andApparatus for Aseptic Canning of Food Products, which is a division ofapplication U.S. Serial No. 688,590, filed October 7, 1957, now PatentNo. 3,035,886.

Aseptic canning processes are carried out in a sterile atmosphere withinan enclosure which contains a container-filling machine and acontainer-closing machine. A food product in a sterile condition isdelivered to the filling machine which packs the presterilized foodproduct into sterile containers. The food-packed containers are thenadvanced to the closing machine where they are closed and sealed. Inaseptic canning operations, it is essential that the filling and closingmachines and their surrounding atmosphere be sterilized prior to thepacking and sealing operations, and also be maintained in a sterilecondition during these operations.

Heretofore, the filling and closing machines have been sterilized withsaturated steam. The sterilization of aseptic canning machinery withsaturated steam at reasonable temperatures requires a relatively longtime, and accordingly, such sterilization is expensive. The timeinterval for the sterilization of canning equipment can be reduced byincreasing the temperature of the saturated steam. However, when thetemperature of saturated steam is increased, the pressure thereofincreases correspondingly. Consequently, it is necessary to usethickwalled chambers to withstand the increase in pressure. Also,heavily constructed chambers are cumbersome and are expensive tomanufacture.

Therefore, an object is to provide an aseptic canning apparatus whereinadjustments and repairs can be made without contaminating the sterileatmosphere in the processing chambers.

Another object is to provide aseptic canning apparatus wherein theenclosure thereof is required to withstand only pressures not materiallygreater than atmospheric pressure.

These and other objects and advantages will be apparent from thefollowing description and the accompanying drawing, in which the singleFIGURE is a diagrammatic illustration of the aseptic canninginstallation of the present invention.

In the aseptic canning method as carried out by the apparatus of thepresent invention, the filling and closing machines, together with theirenclosing chambers, are presterilized. This is accomplished by initiallypurging the atmosphere within the chambers with saturated steam atsubstantially atmospheric pressure. Although saturated steam at higherpressures can be employed, it is desirable to use as low a pressure aspossible to minimize the cost of construction of the enclosure. Thepressure of the steam should be high enough to exceed the atmosphericpressure surrounding the enclosure, thus preventing seepage of unsterileair into the enclosure. Hence, the preferred pressure range for thesaturated steam is from 14.7 p.s.i. to 15 p.s.i. It has been determinedthat generally five minutes of purging time is adequate. However, theprecise time required depends upon the size of the enclosure.

After the atmosphere surrounding the filling and closing machines hasbeen purged, the filling and closing machines together With theirchambers are sterilized with a mixture of steam at substantiallyatmospheric pressure and a chemical bactericide. The steam employed inthe mixture may be either saturated steam or mildly superheated steam.It is to be observed that the steam employed in the steam-bactericidemixture may be at a pressure substantially higher than atmosphericpressure without detracting from the sterilizing er'fectiveness of themixture. For the reasons previously advanced relative to the purgingsaturated steam, the preferred range for the steam employed in themixture of steam and a chemical bac-f tericide is from 14.7 psi. to 15p.s.i.

The chemical bactericides that may be used eiiectively in thesteam-chemical bactericide sterilization are: ammonia, alcohols such asethyl alcohol, aldehydes, acetaldehyde, volatile acids, chlorine,phenolic compounds, and epoxides. It is to be noted, however, thatepoxides, such as propylene oxide and ethylene oxide, are preferred asthe chemical bactericide.

When the chemical bactericide employed is an epoxide in thesteam-epoxide sterilization of aseptic canning apparatus, the preferredconcentration of the epoxide in steam is from 10% to 30% by weight. Ithas been determined that from 10 minutes to 30 minutes of sterilizingtime is adequate for steam-epoxide sterilization of aseptic canningapparatus. However, the precise time required depends upon the size ofthe enclosure.

I have discovered that steam accelerates the lethal action of anepoxide, such as propylene oxide and ethylene oxide, and, thus, reducesthe sterilization time. When propylene oxide or ethylene oxide was usedat concentrations from 5% to 10% by weight in carbon dioxide, thesterilization time required was several hours, while propylene oxide orethylene oxide in concentrations from 10% to 30% by weight in steamrequired less than thirty minutes of sterilization time.

Bacteriological experiments have been performed involving the use ofpropylene oxide and steam for testing the destruction of flat sourorganism #1518 of the National Canners Association. The concentration ofpropylene oxide in steam was from 10% to 30% by weight with exposuresfrom 10 to 30 minutes. These experiments showed high lethality for themixture in relatively short time.

Sterilization tests were conducted by placing 75,000 spores of organism#1518 on petri dishes and then drying them. The dishes were covered sothat the mixture had to find its way into a covered dish. The analysisis based on the following equation for integrated sterilization value(I.S.):

I.S.=D (log mlog s) where D is a constant dependent upon the organismcentration of propylene oxide in steam of 10%, 20% and 30% by weight.The results are given in Table I.

After the filling and closing machines together with their chambers aresterilized with the mixture of steam and a chemical bactericide, theatmosphere within the chambers is again purged with saturated steam atsubstantially atmospheric pressure. The source of steam employed may bethe same source utilized in the initial purge of the atmosphere withinthe enclosures. For the reasons previously advanced relative to theinitial purge of the atmosphere, the preferred pressure range for thesaturated steam is from 14.7 p.s.i. to 15 p.s i. The sec ond purge ofsaturated steam continues until the mixture of steam and a chemicalbactericide is swept from the enclosure. A sterile water rinse may alsobe applied to further cleanse the filling and closing machines. It hasbeen determined that generally five minutes of purging time withsaturated steam is adequate. However, the precise time required dependsupon the size of the enclosure.

Subsequent to the purging of the steam-chemical bactericide mixture fromthe chambers, a sterile medium, such as sterile air or a sterile inertgas, at substantially atmospheric pressure is conducted into thechambers at a suflicient rate of flow for the maintenance of asepsis.Although higher pressures may be employed for the sterile medium, thepressure range preferred for reasons previously advanced is from 14.7p.s.i. to 15 p.s.i.

Upon completion of the presterilization of the filling and closingmachines together with their enclosing chambers, containers and a foodproduct are advanced to the filling machine. Simultaneously, lids areadvanced to the closing machine. While the containers and lids areadvanced to the enclosures of the filling and closing machinesrespectively, they are sterilized by being exposed to saturated steam atslightly above atmospheric pressure. Generally, the pressure range ofthe saturated steam for sterilizing the lids and containers would befrom 15 p.s.i. to 40 p.s.i. However, the precise pressure of thesaturated steam, of course, depends upon the condition of the lids andcontainers. The food product is presterilized and, hence, it is in asterile condition prior to advancement to the filling chamber. The foodprodnot under sterile conditions is packed into the sterilizedcontainers and the food-packed containers are then sealed with sterilelids. During the filling and sealing operations, sterile air or sterileinert gas continues to flow into the filling and closing enclosures sothat the packing and sealing operations are performed in a sterileatmosphere.

The aseptic canning apparatus of the present invention employed in theaseptic canning process comprises a filling machine enclosure or housing1.1 which is open at the bottom and closed at the top and has acylindrical configuration. The enclosure 11 is made of suitable lightsheet metal material, since it is only required to withstand pressuresat substantially atmospheric pressure. Fixed to the top wall 11A of theenclosure 11 are radially extending ribs 12 having an eyebolt 13projecting upwardly at the point of intersection of the ribs. Secured to:the eyebolt .13 is a suitable cable 14 that supports the enclosure 11from an overhead lift mechanism 15 secured to a beam 16 or the like. Theside wall 118 of the enclosure projects downwardly into an annulartrough 17 formed in an open-top cylindrical drum 18 which has a sterileliquid, such as sterile water, therein to provide a liquid seal at thelower end of the enclosure.

The drum 1% may rest on the floor or any suitable support surface. Whilethe preferred embodiment shows a liquid seal for the lower end of theenclosure 11 other suitable means may be employed to seal the lower endof the enclosure. A conventional product filling machine 19 andauxiliary maintenance equipment are mounted within the enclosure 11.

To enable an operator to check and observe the operation of the fillingmachine 19 without contaminating the sterile atmosphere within theenclosure 11, port openings 20 are formed in the wall 113 of theenclosure at convenient observation positions therearound. Disposedwithin the port openings 20 in an airtight manner are panes 21 of glassor other suitable transparent material. In addition, a pair of accessports 22 are formed in the wall 113 at a convenient distance below eachobservation pane 21. Fixed within each pair of access ports 22 in anairtight manner is a pair of gloves 23. Thus, an operator can make thenecessary repairs and clear the jamming of equipment with sterile toolswithout con- Laminating the sterile atmosphere Within the enclosure 11.

The canning apparatus 19 also includes a closing machine enclosure 24which has a cylindrical configuration and is disposed adjacent thefilling machine enclosure 11. The enclosure 24 is closed at the top andopen at the bottom and is made of suitable light sheet metal material,since the only pressure that it is required to withstand issubstantially that of the ambient atmosphere. Fixed to the top wall 24Aof the enclosure 24 are radially extending ribs 25 having an eyebolt 2.7projecting upwardly at their intersections. Secured to the eyebolt 27 isa cable 28 that is part of a lifting mechanism 29 which supports theenclosure from an overhead structure 39. A side wall 243 of theenclosure 24- projects downwardly into an annular trough formed in anopen-top drum 36 which has a sterile liquid, such as sterile water,therein to provide a liquid seal for the bottom of the enclosure 24. Thedrum 36 rests upon the floor or any suitable supporting surface. While aliquid seal is disclosed, other suitable seals may be employed. Aconventional container closing machine 37 and auxiliary maintenanceequipment are mounted within the enclosure 24.

Port openings 38 are formed in the side Wall 2413 of the enclosure 24 atconvenient observation positions therearound. Sealed within the portopenings 38 are panes 41 of glass or other suitable transparentmaterial. A pair of access openings 42 is formed in the wall 24B at aconvenient distance below each pane 41. A pair of gloves 43 is fixedwithin each pair of access ports 42 in an airtight manner. Thus, anoperator can make the necessary repairs and clear the jamming ofequipment within the enclosure 24 with sterile tools withoutcontaminating the sterile atmosphere thereof.

For presterilizing the aseptic canning apparatus 10, a manifold 44 isconnected to the enclosures 1.1 and 24. Communicating with the manifold44 is a steam supply conduit 45 having a control valve 46. Eithersaturated steam or superheated steam may be conducted through theconduit 45 for delivery to the enclosures 11 and 24 through the manifold44'. Also, communicating with the manifold 44 is a conduit 47, whichincludes a control valve 48. Through the conduit 47 is conducted themixture of steam and a chemical bactericide, such as steamepoxidemixture, which flows through the manifold 44 for delivery to theinterior of the enclosures during the presterilizing operation. Inaddition, a conduit 49 having a valve 50 is connected to the manifold 44to conduct either sterile air or a sterile inert gas to the manifold 44for delivery to the interior of the enclosures 11 and 24. The sterileair or sterile inert gas is delivered to the interior of the enclosuresupon completion of the sterilization of the aseptic canning apparatus 10and continues to flow during the filling, closing and sealing operationsin order to maintain an aseptic atmosphere. Vents 52 and 53 are providedin the tops of the enclosures 11 and a 24, respectively, to provide anescape Outlet for steam and gases. When the bottoms of the enclosuresare provided with liquid seals, the atmospheric pressure within theenclosures should not exceed the liquid pressure in the annular troughs17 and 35, respectively, which liquid pressure is determined by theheight of the liquid above the bottom edges of the enclosures 11 and 24.

Containers 54 are advanced on a suitable conveyor 55 to a transfer valve56. The transfer valve 56 includes pockets or compartments formed alongthe peripheral edge of a feed wheel (not shown) which is disposed insidethe casing 57 of the transfer valve. A suitable opening 57a is formed inthe casing 57 so that only one pocket at a time is in registry with theopening. Suitable means, not shown, rotate a shaft 58, which, in turn,rotates the compartmented feed wheel to deposit the containers 54 intoan airtight passageway provided by a housing 59. The housing 59 has anend portion sealed in an opening in the wall 11B so that the passagewayprovided by the housing, communicates with the interior of the enclosure11. Within the passageway are suitable means, not shown, for advancingthe containers 54 into the filling machine. Connected to the housing 59is a conduit 6t) that conducts saturated steam into the passageway inthe housing 59 for exposing the containers 54 to a sterilizingatmosphere as they are advanced into the enclosure 11. With thisarrangement, the containers 54 are sterilized as they are advanced tothe filling machine 19.

It is to be observed that the saturated steam in the passageway inhousing 59 does not escape through the transfer valve 56, since thepocket of the feed wheel that is in registry with the passageway is notin communication with the inlet opening of the valve 56. Likewise, anyentry of unsterile air through the transfer valve 56 is negligible,since the casing opening 57a is in registry with only one compartment ata time.

A product conduit 61 is connected to the enclosure 11 in an airtightmanner and is arranged to have a presterilized food product passtherethrough. The presterilized food product is delivered to the fillingmachine 19, which packs the presterilized food product into the sterilecontainers 54. After being filled, the containers are advanced from theenclosure 11 to the enclosure 24 through an airtight conduit 62. Theconduit 62 is received in sealed relation in openings in the Walls 11Band 24B of the enclosures 11 and 24, respectively.

Container lids or covers 63 are advanced to the enclosure 24 of theaseptic canning apparatus through a conduit 64 having thereinlid-admitting valves 65 and 66. The conduit 64 passes through the topwall 24A of the enclosure 24 and communicates with the closing machine37. A conduit 67 for conducting saturated steam is connected to theconduit 64 between the lidadmitting valves 65 and 66. In operation, thelid-admitting valve 65 is first actuated to permit the lids to advancein the conduit 64 to the lid-admitting valve 66. During this period ofadvancement, the lids 63 are exposed to the sterilizing atmosphere ofsaturated steam. After the lids are sterilized, the lid-admitting valve66 is actuated to permit the lids 63 to advance to the closing machine37. Thus, the lids 63 are delivered to the closing machine 37 in asterile condition with a negligible escape of steam through the conduit64.

After the closing machine 37 seals the food-packed containers with thelids 63, the sealed containers are advanced by suitable means, notshown, through an airtight conduit 68 to a transfer valve 69. Theconduit 68 is connected at one end in the wall 243 of the enclosure 24in an airtight manner and at the other end communicates with thetransfer valve 69. The transfer valve 69 has a feed wheel (not shown)disposed in a housing 70. The Wheel has pockets or compartments formedalong the peripheral edge thereof. A suitable discharge opening (notshown) is formed in the housing 70 so that one pocket at a time may comeinto registry therewith.

Suitable means, not shown, are provided to rotate a shaft 73 of thevalve 69, which in turn, rotates the wheel to bring the pocketssuccessively into registry with the discharge opening so that the sealedcontainers may be discharged one at a time onto a conveyor 72. Since thedischarge opening of valve 69 can register with only one pocket at atime, only a negligible amount of unsterile air can enter the conduit 68through the transfer valve '69. The conveyor 72 advances the sealedcontainers to a suitable loading platform, not shown.

Connected to the enclosure 11 and to the enclosure 24 are conduits 74and 75, respectively, which conduct sterile rinse water to the interiorof the enclosures. Connected to the conduits 74 and 75 are suitablehoses 76, only one being shown, which are disposed in the enclosures andare accessible to the operator. 7

In carrying out the process of aseptic canning of food products incontainers, the aseptic canning apparatus 10 is presterilized. This isaccomplished by opening the control valve 46 in the steam supply conduit45 to cause the saturated steam to flow into the filling enclosure 11and into the closing enclosure 24 through the manifold 44. The flow ofsaturated steam purges the atmosphere within the enclosures 11 and 24.After the atmosphere within the enclosures is purged, the control valve46 is closed. Thereupon, the control valve 48 in conduit 47 is opened,causing the mixture of steam and a chemical bactericide to flow into thefilling enclosure'll and into the closing enclosure 24 through themanifold 44. The steam-chemical bactericide mixture is permitted tocirculate in the enclosures until the aseptic canning apparatus issterilized. When the filling machine 19 and the closing machine 37,together with the surrounding atmosphere, are sterilized, the valve 43is closed. Then, the valve 46 in conduit 45 is again opened, permittingsaturated steam to flow once more into the enclosures 11 and 24. Theflow of saturated steam into the enclosures purges the atmospherecontained therein, and sweeps the mixture of steam and a chemicalbactericide out of the enclosure through the vents 52 and 53. After theenclosures have been purged, the valve 46 is closed to shut off thesupply of saturated steam and the valve 5% in conduit 49 is opened. Theopening of valve 50 causes sterile air or sterile inert gas to fiow intothe enclosures 11 and 24 through the manifold 44. The flow of sterileair or sterile inert gas into the enclosures is continued during thefilling and sealing operations in order to maintain an asepticatmosphere within the enclosures.

After the aseptic canning apparatus 10 has been presterilized, thefilling operation begins with the containers 54 being advanced to thetransfer valve 56. The transfer valve 56 transfers the containers 54from the conveyor to the passageway in housing 59, wherein thecontainers are advanced to the filling machine 19. During the time thecontainers 54 are in the passageway, steam is conducted from the conduit60 into the passageway to expose the containers 54 to a sterilizingatmosphere. Hence, the containers 54 are sterilized as they are advancedto the filling machine 19.

Simultaneously with the advancing of the containers 54 to the fillingmachine 19, a presterilized food product is conducted in the conduit 61to the filling machine 19. The filling machine 19 packs thepresterilized food product into the sterile containers 54. Thefood-packed containers are then advanced through the passageway 62 intothe enclosure 24 for delivery to the closing machine 37.

While the food-packed containers are advanced to the closing machine 37,a supply of lids 63 is disposed in the conduit 64. The lid-admittingvalves 65 and 66 are actuated to deliver a supply of lids to the closingmachine 37. During the time the lids advance from valve 65 to valve 66,they are exposed to an atmosphere of saturated steam conducted to theconduit 64 by the conduit 67. Thus, the lids 63 are sterilized as theyare advanced to the closing machine 37 in enclosure 24. The

closing machine 37 seals the food-packed containers with the sterilizedlids 63 and the sealed containers are then advanced through the conduit68 to the transfer valve 69 which transfers the sealed containers to theconveyor 72 on which they are carried to a loading platform, not shown.

Whereas, the preferred embodiment of the present invention shows twoaseptic enclosures, it is to be understood that the aseptic canningmethod can be performed in a single or unitary chamber containing thepacking and sealing machines. Although steam-chemical bactericidesterilization, such as steam-epox ide sterilization is described inconnection with the canning apparatus in the enclosures, it is apparentthat the sterilization process can be applied to other articles such ascontainers and lids.

It will be understood that modifications and variations of theembodiments of the invention disclosed herein may be resorted to withoutdeparting from the spirit of the invention and the scope of the appendedclaims.

Having thus described my invention, What I claim as new and desire toprotect by Letters Patent is:

1. In an apparatus for aseptically packing food products, a drum havingan open upper end, means in said drum for processing containers, atrough formed at the open end of said drum having a sterile non-toxicliquid confined therein, an enclosure having a closed upper end and adownward extending wall, said wall having an open bottom defined by alower edge, means for suspending said enclosure with said lower edgethereof disposed in the liquid in said trough wherein said liquid actsas a pressure seal, means for directing a sterilizing medium into saidenclosure to sterilize said processing means and the space within saiddrum and said enclosure, and means for directing a sterile gas into saidenclosure at a pressure below that which will disturb the liquid sealdefined by the liquid in said trough to maintain a sterile atmosphere insaid enclosure.

2. In an apparatus for aseptically packing food products, a drum havingan open upper end, means in said drum for processing containers, atrough formed at the open end of said drum having a non-toxic sterileliquid therein, an enclosure having a closed upper end and a downwardlyextending wall, said wall having an open bottom defined by a lower edge,means for suspending said enclosure with said lower edge thereofdisposed in the liquid in said trough wherein said liquid acts as apressure seal, means for directing a sterilizing medium into saidenclosure to sterilize said processing means and the space within saiddrum and said enclosure, means for directing a sterile non-toxic gasinto said enclosure at a pressure below that which will disturb theliquid seal defined by the liquid in said trough to maintain a sterileatmosphere in said enclosure, said enclosure having an observation portand an access opening therein, a transparent Window closing saidobservation port in fluid tight engagement, and a fluid impervious glovesecured in fluid tight engagement to said access opening wherebyadjustments can be made and observed within the sterile atmosphereencompassed by said enclosure without contaminating the sterilenon-toxic atmosphere.

3. In an apparatus for aseptically packing food products, a two-sectionhousing having a lower section and an upper section, said upper sectionhaving a closed upper end and a downwardly extending wall having a loweredge, means in said housing for processing containers, a trough securedto said lower section providing a reservoir for a bath of non-toxicsterile liquid, means for supporting said upper section with said loweredge thereof positioned in the liquid in said trough wherein said liquidacts as a pressure seal, means for directing a sterilizing medium intosaid housing to sterilize said processing means and the space withinsaid housing, and means for directing a nontoxic sterile gas into saidhousing at a pressure below that which will disturb the liquid sealdefined by the liquid in said trough to maintain a sterile atmosphere insaid housing.

References Cited in the file of this patent UNITED STATES PATENTS903,853 Gartner Nov. 17, 1908 976,619 Barker Nov. 22, 1910 1,642,577Carson Sept. 13, 1927 2,170,579 Sperry Aug. 22, 1939 2,651,192 LoweSept. 8, 1953 2,839,355 George June 17, 1958 2,855,314 Martin Oct. 7,1958 2,862,821 \Vilbur et a1 Dec. 2, 1958

1. IN AN APPARATUS FOR ASEPTICALLY PACKING FOOD PRODUCTS, A DRUM HAVINGAN OPEN UPPER END, MEANS IN SAID DRUM FOR PROCESSING CONTAINERS, ATROUGH FORMED AT THE OPEN END OF SAID DRUM HAVING A STERILE NON-TOXICLIQUID CONFINED THEREIN, AN ENCLOSURE HAVING A CLOSED UPPER END AND ADOWNWARD EXTENDING WALL, SAID WALL HAVING AN OPEN BOTTOM DEFINED BY ALOWER EDGE, MEANS FOR SUSPENDING SAID ENCLOSURE WITH SAID LOWER EDGETHEREOF DISPOSED IN THE LIQUID IN SAID TROUGH WHEREIN SAID LIQUID ACTSAS A PRESSURE SEAL, MEANS FOR DIRECTING A STERILIZING MEDIUM INTO SAIDENCLOSURE TO STERILIZE SAID PROCESSING MEANS AND THE SPACE WITHIN SAIDDRUM AND SAID ENCLOSURE, AND MEANS FOR DIRECTING A STERILE GAS INTO SAIDENCLOSURE AT A PRESSURE BELOW THAT WHICH WILL DISTURB THE LIQUID SEALDEFINED BY THE LIQUID IN SAID TROUGH TO MAINTAIN A STERILE ATMOSPHERE INSAID ENCLOSURE.